/**
 * @classDescription 模拟Marquee，无间断滚动内容
 * @author Aken Li(www.kxbd.com)
 * @DOM
 *  	<div id="marquee">
 *  		<ul>
 *   			<li></li>
 *   			<li></li>
 *  		</ul>
 *  	</div>
 * @CSS
 *  	#marquee {overflow:hidden;width:200px;height:50px;}
 * @Usage
 *  	$("#marquee").kxbdMarquee(options);
 * @options
 *		isEqual:true,		//所有滚动的元素长宽是否相等,true,false
 *  	loop:0,				//循环滚动次数，0时无限
 *		direction:"left",	//滚动方向，"left","right","up","down"
 *		scrollAmount:1,		//步长
 *		scrollDelay:20		//时长
 */
(function ($) {
    $.fn.kxbdMarquee = function (options) {
        var opts = $.extend({}, $.fn.kxbdMarquee.defaults, options);

        return this.each(function () {
            var $marquee = $(this); 			//滚动元素容器
            var _scrollObj = $marquee.get(0); 	//滚动元素容器DOM
            var scrollW = $marquee.width(); 	//滚动元素容器的宽度
            var scrollH = $marquee.height(); 	//滚动元素容器的高度
            var $element = $marquee.children(); //滚动元素
            var $kids = $element.children(); 	//滚动子元素
            var scrollSize = 0; 				//滚动元素尺寸

            //滚动类型，1左右，0上下
            var _type = (opts.direction == "left" || opts.direction == "right") ? 1 : 0;

            //防止滚动子元素比滚动元素宽而取不到实际滚动子元素宽度
            $element.css(_type ? "width" : "height", 10000);

            //获取滚动元素的尺寸
            if (opts.isEqual) {
                scrollSize = $kids[_type ? "outerWidth" : "outerHeight"]() * $kids.length;
            } else {
                $kids.each(function () {
                    scrollSize += $(this)[_type ? "outerWidth" : "outerHeight"]();
                });
            };

            //滚动元素总尺寸小于容器尺寸，不滚动
            if (scrollSize < (_type ? scrollW : scrollH)) { return; };

            //克隆滚动子元素将其插入到滚动元素后，并设定滚动元素宽度
            $element.append($kids.clone()).css(_type ? "width" : "height", scrollSize * 2);

            var numMoved = 0;
            function scrollFunc() {
                var _dir = (opts.direction == "left" || opts.direction == "right") ? "scrollLeft" : "scrollTop";
                if (opts.loop > 0) {
                    numMoved += opts.scrollAmount;
                    if (numMoved > scrollSize * opts.loop) {
                        _scrollObj[_dir] = 0;
                        return clearInterval(moveId);
                    };
                };

                if (opts.direction == "left" || opts.direction == "up") {
                    var newPos = _scrollObj[_dir] + opts.scrollAmount;
                    if (newPos >= scrollSize) {
                        newPos -= scrollSize;
                    }
                    _scrollObj[_dir] = newPos;

                    //yu20120111
                    if (opts.stopTime!=0)
                        if ((newPos % scrollH) == 0) { clearInterval(moveId); $(this).stop().delay(opts.stopTime).queue(function () { moveId = setInterval(scrollFunc, opts.scrollDelay); return; }); }
                    

                } else {
                    var newPos = _scrollObj[_dir] - opts.scrollAmount;
                    if (newPos <= 0) {
                        newPos += scrollSize;
                    };
                    _scrollObj[_dir] = newPos;

                    //yu20120111
                    if (opts.stopTime != 0)
                        if ((newPos % scrollW) == 0) { clearInterval(moveId); $(this).stop().delay(opts.stopTime).queue(function () { moveId = setInterval(scrollFunc, opts.scrollDelay); return; }); }
                };
            };

            //滚动开始
            var moveId = setInterval(scrollFunc, opts.scrollDelay);

            //鼠标划过停止滚动
            $marquee.hover(function () {
                clearInterval(moveId);
            }, function () {
                clearInterval(moveId);
                moveId = setInterval(scrollFunc, opts.scrollDelay);
            });
        });
    };

    $.fn.kxbdMarquee.defaults = {
        isEqual: true, 	//所有滚动的元素长宽是否相等,true,false
        loop: 0, 		//循环滚动次数，0时无限
        direction: "left", //滚动方向，"left","right","up","down"
        scrollAmount: 1, 	//步长
        scrollDelay: 20, //时长
        stopTime: 0 //每次滚动挺对时间， 0为不停顿  //yu20120111
    };

    $.fn.kxbdMarquee.setDefaults = function (settings) {
        $.extend($.fn.kxbdMarquee.defaults, settings);
    };
})(jQuery);